Changes of Oxygen Tension in Tumours Induced by Vasoconstrictor and Vasodilator Drugs

In the last few years it has become important to obtain information about the physiology of the blood vessels and circulation in tumours in order that new techniques in radiotherapy and chemotherapy can be fully exploited in the treatment of cancer.The importance of oxygen tension to radiosensitivity is now well recognised.GRAY (1957) has reviewed the radiobiology of the oxygen effect, and MIT-CHELL (1957 a, b, 1960) has used oxygen administered at atmospheric pressure as a radiosensitiser in radiotherapy since 1953 ; HULTBORN and FORSSBERG (1954) report on its use during irradiation of four cases with skin tumours, while CHURCHILL-DAVIDSON, SANGER and THOMLINSON ( 195 7) have treated a number of patients with radiation and oxygen at a pressure of 3 or 4 atmospheres.It is clear that if oxygen is to be used as a radiosensitiser in a rational manner it is important to know the oxygen tension of tumour and normal tissues and the change in oxygen tension that occurs when oxygen is breathed.Our experience with the oxygen-cathode of DANNEEL ( 1897-98) for observing changes in oxygen tension in vivo (several papers by CATER, PHILLIPS and